Raised Hb F analysis
- Description
- In adults Hb F represents <1% of the total haemoglobin. There are however acquired and inherited disorders in which increased levels of Hb F are found in adult life. Acquired increases in Hb F are restricted to conditions where there is an increase in erythropoietic production and appear to be a secondary response to an underlying condition. Inherited conditions associated with a raised Hb F, include Hereditary Persistence of Fetal Haemoglobin (HPFH), some Hb variants and delta beta thalassaemia. Some beta thalassaemia mutations can also be associated with a raised Hb F. HPFH is characterised in heterozygotes by levels of Hb F of 15-25% with normal red cell indices. Delta beta thalassaemia tends to have lower levels of Hb F (5-15%), microcytic, hypochromic red cells in heterozygotes with detectable chain imbalance. Accurate diagnosis is essential since HPFH is clinically benign compared with delta beta thalassaemia in which the individual may be dependent on blood transfusions throughout life. HPFH and delta beta thalassaemia arise from large deletions of the beta globin locus on chromosome 11, all of which remove or destroy the expression of the delta and beta globin genes. There are also point mutations in the promoter of the gamma globin genes which can also give rise to HPFH. Based on the clinical details, haematological data and ethnic origin, patients will be assessed on an individual basis for the best approach for clinical testing.
- Clinical details
- Please state if a pregnancy is involved as antenatal work is prioritised. Please identify partner in referral if a fetal risk assessment is required. Please provide full blood count (FBC) and HPLC screening results and iron levels as they become available.
- Testing site
- Synnovis : Genomics : King's College Hospital
- Sample type and volume required
- Volume of blood anticoagulated with EDTA: Adult (16 years and above) 2 x 4 ml, Children (2-15 years) 1 or 2 x 4 ml Infants (0-2 years) 1 ml. Clotted samples are unsuitable for DNA analysis. Blood Samples in in correct anticoagulant tubes may be rejected. We accept DNA samples. Please provide at least 1-5µg of purified DNA For prenatal diagnosis please refer to section for sample requirements.
- Special sample instructions
Samples must be clearly labelled with the patients first name, surname, D.O.B, hospital number and the date the sample was taken. The details on the sample must correspond to the request form. Unlabelled samples will not be accepted.
- Storage and transport
- Blood should be stored at 4°C where possible. Send at room temperature by first class post. If possible, please complete the request form attached and send as a hard copy (do not send electronically) with the sample. This will ensure all relevant information is available and will aid us in processing your test.
- Turnaround time
- 20 working days from sample receipt. For complex cases where additional tests are required each test will add 10 working days. In antenatal patients 10 working days from sample receipt. Please note any clinical urgency on the referral form, so samples can be prioritised.
- Cost
- Please contact Business Development for pricing enquiries
- Contacts
Special Haematology Department St Thomas’ Hospital
Phone – 020 7188 8189
St Thomas’ Hospital
5th Floor – North Wing
Westminster Bridge Road
London SE1 7EHSpecial Haematology Department at Guy’s Hospital
Phone – 020 7188 3421
Guy’s Hospital
4th Floor – Southwark Wing
Great Maze Pond
London SE1 9RTRed Cell Centre – Protein Laboratory
Phone: 020 3299 2455
Email: kch-tr.redcelllab@nhs.net
Central Specimen Reception
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
Denmark Hill
London SE5 9RS